Stop mechanism for sewing machines



a. w. NELSON STOP MECHANISM FOR SEWING MACHINES I 'Fil'ed March 21. 1923 ,2 Sheets-Shut '1 HISATTORNEY -June 2, 1925. 1,539,360

G. w. NELSON STOP MECHANISM FOR SEWING MACHINES File March '21. 1923- 2 Sheets-Shed 2 Patented June 2, 1925.

UNITED srares 1,539,860 PATENT OFFICE.

GEORGE W. NELSON, OE CLEVELAND, OHIO, ASSIGNOR- TO THE STANDARD SEWING MACHINE COMPAI'IY, OF CLEVELAND, OHIO, A CORPORATION OF OHIO.

STOP MECHANISM FOR SEWING MACHINES.

Application filed March 21, 1923 Serial No. 626,637.

To all whom it may concern:

Be it known th t 1, Greece XV. NELSON, a citizen of the United States, and a resident of Cleveland, in the county of Cuyahoga and State of Ohio, have invented crtain new and useful Improvements in Stop Mechanism for Sewing Machines; and T (lo hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

This invention relates to stop mechanism for sewing machines and more particularly to stop mechanism for that class of sewing machines in which successive groups or series of stitches are made at separated points in the work, as, for example, in but ton sewing machines, suchas disclosed in January 8, 1918.

The main object of the present invention is the provision of an improved mechanism, more simple in construction and efficientin operation than those heretofore used, for automatically stopping the machine'on the completion of predetermined series or groups of stitches, quickly and without undue jar or strain on the machine parts.

This and other objects to be hereinafter referred to are attained by the improvements constituting my invention, which latter in one embodimentthereof is illus trated in the accompanying drawings, in Whiclr-- Figure l is a rear end elevation of the lower part of a sewing machine equipped with my improvements, the parts being shown in the positions they occupy when the machine is in operation.

Fig. 2 is a similar view with certain of the parts broken away and in section, the parts shown being in the positions they occu 3y when the machine is stopped.

Fig. 3 is a view looking from the right in Fig. 1, or at the rear side of the machine, and showing the parts in position just at the time the stop mechanism has been released and thrown into action.

Fig. 4 is a view of the parts from the front of the machine or from the side opposite that shown in Fig. 3, and

Fig. 5 is a detail showing the outer hub of the loose driving pulley and the cam for forcing said pulley into clutching engage- .iietters Patent No. 1,252,931, granted to'me' Similar reference numerals indicate like' parts in the several figures of the drawings.

The sewing machine here shown as equipped with my invention embodies a main frame comprising upper and lower portions, 2 and 3, suitably connected and adapted for the support of the various parts of the operating mechanism. Suitably journalled in the lower portion 3 of the frame is the main shaft 4, which extends lengthwise of said lower portion 3 and from which the several operating parts of the machine are driven through suitable connections in usual manner. This shaft 4: at its rear end projects beyond the adjacent end of the frame for the association therewith of the starting and stopping mechanism which vill now bedescribed.

On the projecting end ofthe shaft 4 is a disc 5 and a driving pulley 6, the said disc being fast on the shaft and the driving pulley being loose thereon for movement to and from a position of frictional clutching engagement with the disc. In order to assure proper clutching engagement between the driving pulley and the disc, the pulley is preferably provided on that face adjacent the disc with a friction ring 7 of leather, fiber, or other like material.

As a means for moving the driving pulley into clutching engagement with the disc 5.

and releasing it therefrom, I have provided a controller 8 adapted for movei'nent in a plane parallel with the end face of the driving pulley and having a cam face for engagement with said pulley preferably with an anti-friction ball 9 seated in the hub thereoftho said cam face having a high part 10, which, when in engagement with the ball 9, will hold the pulley in clutching engagement with the fast disc, and having a low part 11, which, when shifted to a position opposite said ball 9, as shown in Fig. 5, will permit of the release of said pulley from clutching engagement with the fast I disc. This controller is carried by an arm 12 of a rocking frame 1& which is mountd on a pivot stud 15 attached to and projecting from one side of the machine frame 3, the said rocking frame being removably held on this stud by a headed screw 16 threaded into the end of the latter. The controller carrying arm 12 is here shown as formed with a split hub lit) . 17 which is rigidly clamped on the outer end of the hub of the rocking frame 14 by means of a clamping screw 18. It will be obvious however that the arm 12 may be formed as an integral part of the rocking frame if so desired. The controller 8 has an arm 20 extending therefrom in a direction parallel with the axis of the driving pulley, which is adjustably held within a seat 21 in the arm 12 by suitable fastening means, such as the screws 22. This connection permits of the cam face of the controller being adjusted with respect to the hub of the driving pulley for causing the latter to properly coatt with the fast disc5.

During operation of the machine in the formation of a group of stitches, the driving pulley, as hereinbefore stated, is held in clutching engagement with the fast disc 5 by the engagement of the high part 10 of the controller cam with the ball 9 in the hub of the pulley. Such position of the controllercam is maintained" by the engagement of a latching device 25 on the machine frame with a notched latch member 26 on the rocking frame 14, as shown in Fig. 1. Upon the completion of a predetermined series or groups of stitches, the said latching device 25, here shown in the form of a bell-crank lever, is automatically tripped to release the rocking frame 14 and permit it to be thrown forward to thereby advance the high part 10 of the controller cam from engagement with the driving pulley and so release the latter from clutching engagement with the fast disc 5. When the rocking frame 14 is thus released by the latching device, it isthrown forward or in the direction of the shaft 4, as described, by means of a spring 27 which connects at one end with an arm 28 of said frame 14 and at its opposite end with a pin 29 on a fixed arm 30 projecting fromrthe frame 3. l

The latching device may bet-ripped by any suitable means. Preferably the tripping means is operated from the main shaft 4 through a cross-shaft 3]. driven from said main shaft by gearing (not shown), by means of which a relatively slow rotary movement is imparted to this cross-shaft. On the completion of a predetermined group of stitches, the cross-shaft is intended to bring into operation a releasing device. This releasing device is shown as carried by a disc 32 on the end of the cross-shaft and is in the form of aradial'pin 33, slidable in and out of operative position and suitably held in place. When projected into operative position as shown in Fig. 3, it is brought, on each complete rotation of the cross-shaft, into engagement with the lower end 34 of the latching lever, and rocks the latteron its pivot in adirection to disengage its upper arm from the notchedlatch member 26, as shown in Fig. 3, whereupon the parts will act to release the driving pulley from clutching engagement with the fast disc 5 in the manner previously described. A swingin plate 35 normally coversthis latch trlppin means.

To start t e machine following 'the release of the driving pulley as described, the

frame 14 is rocked backward from its recrumed on a stationary stud 37 and ar- 7 ranged'with one arm 38 extending beneath an arm 39 of the rocking frame 14 for en-' gagement therewith, and its other arm 40 extending to a suitable postion for connection with the treadle (not shown), or other similar operating device.

When the frame 14 is rocked backward under the action of the lever 36, it is limited .0

in its backward movement by the engagement of a stop surface 41 thereon with the adjacent wall of the fixed arm 30, as shown in Fig. 1, and when said frame reaches such backward position the latching lever 25 is automatically caused to snap into holding engagement with the latch member -26 on the frame under the action of a springpressed pin 43, which latter is supported Within a chamber in the arm 30 with one end projecting beyond the latter'into press- 7 mg engagement-with the lower arm of the latching lever as shown in Fig.3. It will be clear by reference to the latter figure, that the action of the pin 43 against the latching lever, not only acts to throw the lever 25 into latching engagement with the notched member 26 on the frame 14, but that it also serves to hold the lower or vertical arm of said lever in position to be engaged by the releasing device 33.

\Vhen the driving pulley is released from the. iast disc 5, the shaft 4 will continue its rotation for sometime under momentum unless sooner brought to a stop, and as this momentum is very considerable when the machine is being operated at high speed, and

as it is desirable that the machine should be quickly brought to a stop following the release of the driving pulley and with the parts in definite predetermined positions, I have provided a braking or stopping device that will be operative to come into action immediately upon the release of the driving pulley and bring the shaft 4 and its-driven parts to a stop in the desired positions without injurious jar or strain to the same. The

stopping means employed for this purpose comprise a stop member on the shaft 4, here shown as a disc 50 fast on said shaft and a peripheral notch 51, and a co-operatin stop device 52 supported within a cyl .idrical chamber 53 in the rocking frame 14- between buffer springs 5%, 54, and hava projection on that side adjacent the disc 50 for engagement with the latter in its said notch 51. With this construction and arrangement of parts, when the frame 14 is thrown back to its latched position with the controller 8 holding the driving pulley in clutched engagement with the fast disc 5, as shown in Fig. 1, the supported stop device 52 is held back from position. for cooperation with the notched disc 50 on the shaft 4:, but when said rocking frame is automatically released by its latching device and thrown forward by the spring 27 to effect the release of the driving pulley, the supported stop device 52 is thereby thrown forward to bring its projection 55 into engagement *ith the peripheral edge of the disc 50, on which it rides until the notch 51 has been rotated to a position opposite the same, which time it is caused to snap into said notch under the action of the spring 27 and bring the shaft lto a stop in a definite predetern'iined position. This stopping of the shaft is effected without injurious ar or strain on the machine parts by reason of the buffer springs 54:, 5%, at the opposite ends of the stop device which act to cushion the end thrusts of the latter as produced, first, by the forward rotation of the disc fol.- lowing its engagen'ient with the stop projection 55, and next, by the rebound movement of the disc following its stoppage in the direction of its forward rotation. The engagement of the stop projection 55 with the disc 50 takes place through a vertical slot or opening 57 in the front wall of the chamber in which the stop device 'is located, as shown in Fig 2. The stop (l( '\'l-:(

2 and its buil'er springs 54. are adapted to be placed in and removed from the chan'iber 5 hro o the upper end of said chamber, which is closed by are-movable cup threaded on the upper end of the (han1ber-containing arm of the frame as shown. This means for supporting the stop devic: and its buffer springs in connection with the rocking frame ll is a very imporant feature of the invention in that it permits of ready and convenient assembling of too parts and subsequent replacement of the same if necessary.

A further and important feature incident to this way of supporting the said parts, i. e., the stopping device and its buffer springs, is that the vertical position of the stopping device, and also the tension of the buffer springs, may be adjusted by merely raising or lowering the threaded cap 58 constituting the end wall of the chamber.

The latch member 26 on the rocking frame llis in the form of a short rod adjustably held at one end within a socket or opening in said frame by means of set screws 60. By adjusting this member back and forth in its said opening in the frame, the position of the latter and its supported parts, such as the stop device 52 and the controller 8, may be suitably adjusted wi h respect to their cooperating parts on the shaft The clamped connection of the controller carrying arm 12 with the hub of the rocking frame 1%, as hereinbcfore described, also permits of the controller 8 being adjusted with respect to the driving pulley, if so desired, independently of any adjustment of the said rocking frame.

What I claim is:

1. In a sewing machine, the combination with its operating shaft, of a stop member fixed on said shaft, a movable frame having a chamber open at one side thereof, a stop device in said chamber for cooperating through the open side thereof with the stop member on the shaft, spring buffers in said chamber engaging the stop device at opposite ends thereof, and means for shifting the frame to bring its supported stop device to and from position for cooperation with the stop member on the shaft.

2. In a sewing machine, the combination with its operating shaft, of a stop member fixed on said shaft, a movable frame having a chamber open at one side thereof, a stop device in said chamber for cooperating through the open side thereof with the stop member on the shaft, spring bufi'ers in said chamber engaging the stop device at opposite ends thereof, a latch holding the frame with its supported stop device in inoperative position relative to the stop member on the shaft, and automatic means for releasing the latch and shifting the frame to bring its supported stop device to position for cooperation with the stop member on the shaft.

3. In a sewing machine, the con'ibination with its operating shaft, of a stop member fixed on said shaft, a movable frame having a chamber open at one side and at one end, a stop device in said chamber for cobperating through the open side thereof with the stop member on the shaft, spring buffers in the chamber engaging the stop device at opposite ends thereof, a removable cap at the end opening of said chamber for removably retaining in the latter the said stop device and buffer springs, and means for shifting the'frame to bring its supported stop device to and from position for cooperation with the stop member on the shaft.

4. In a sewing machine, the combination with its operating shaft, of a disc fixed on said shaft having a notch in its peripheral edge, a movable frame having a chamber open at one side thereof, a stop device in said chamber having a lateral projection for engaging in the notch of the disc on the shaft through the open side of the chamber,

spring bufi'ers in the chamber engaging the stop device at opposite ends thereof, and means for shifting the frame to bring its supported stop'device to and from position for cooperation with the notched disc on the shaft.

5. In a sewing machine, the combination with its operating shaft, of a stop member fixed on said shaft, a pivoted frame having a cylindrical chamber open at one side and at one end, a stop device located in and movable lengthwise of said cylindrical chamber for cooperating through the open side thereof with the stop member on the shaft, spring buffers in said chamber engaging the stop device at opposite ends thereof, a removable cap at the end opening of said chamber for removably retaining in the latter the said stop device and buffer springs, a latch device normally holding the frame with its supported stop device in inoperative position, a spring for rocking the frame and supported stop device to operative position, and automatic means for releasing said latch device.

6. In a sewing machine, the combination with its operating shaft, of a stop member on said shaft, a movable frame carrying a stop device for cooperating with said stop member, a latch member connected with said frame, a latching lever pivoted on a stationary support for cooperating with the latch member on the movable frame to hold the latter and its supported stop device in inoperative position, automatic means for releasing the latching lever from engagement with the latch member on the movable frame, a stationary member having a chamber open at one end, and a spring-pressed pin mounted in said chamber with one end projecting therefrom for engaging the latching lever and yieldingly holding it in nor mal latching position.

7 In a sewing machine, the combination with its operating shaft, of a stop member fixed on said shaft, a movable frame having a chamber open at one side thereof, stop device in said chamber for cooperating through the open side thereof with the stop member on the shaft, spring buffers in said chamber engaging the stop device at opposite ends thereof, and means for adjusting the tension of said spring buffers in the chamber.

8. In a sewing machine, the combination with its operating shaft, of a stop member fixed on said shaft, a movable frame having a chamber open at one side thereof, a stop device in said cha'mberfor cooperating through the open side thereof with the stop member on the shaft, spring buffers in said chamber engaging the st-o device at opposite ends thereof, and an a justable end wall forsaid chamber operative to adjust the tension of the spring buffers in the chamber. 9. In a sewing machine, the combination with its operating shaft, of a stop member fixed on said shaft, a movable frame having a chamber open at one side thereof, a stop device in said chamber for cooperating through the open side thereof with the stop member onthe shaft, spring buffers in said chamber engaging the stop device at opposite ends thereof, and means for adjusting Elie position of the stop device in said cham- 10. In a sewing machine, the combination with its operating shaft, of a stop member fixed on said shaft, a movable frame having a chamber open at one side thereof, a stop device in said chamber for cooperating through the open side thereof with the stop member on the shaft, spring buffers in said chamber engaging the stop device at oppo site ends thereof, and means for adjusting the tension of the buffer springs and also the position of the stop device in said chamber.

11. In a sewin machine, the combination of its operating s aft having thereon a loose driving pulley, a fast clutch disc and a stop member, a pivoted frame having its axis parallel with that of the shaft and having an arm carrying a controller cam for moving the driving pulley into clutching engagement with the clutch disc, said frame also having a chamber open at one side thereof, a stop device in said chamber for cooperating through the open side thereof with the stop member on the shaft, spring bnfiers in said chamber engaging the stop device at the opposite ends thereof, means for adjusting the tension of the buffer springs and also the position of the stop device in said chamber, and means for rocking the frame to shift the supported controller cam and stop device to and from their operative position.

In testimony whereof I affix my signature.

GEORGE NELSGN. 

